What is the Difference Between Physical and Chemical Sunscreen?

Sunscreen is the most important anti-aging skincare product you can use. It protects your skin from harmful UV rays, which come in two types: UVB and UVA. UVB rays are associated with sunburns and UVA rays are responsible for causing our lovely fine lines, wrinkles, discolorations, and other signs of aging. 

More importantly sunscreen also prevents skin cancer, especially UVA rays. But, all sunscreens are not created equal.

There are two main types of sunscreen: Physical and Chemical

Physical Sunscreen

Physical sunscreen, also called mineral sunscreen, contains minerals like zinc oxide and titanium oxide that sit on the surface of the skin. These create a physical barrier that reflects the sun’s rays and prevents them from affecting our skin. These are recommended most by aestheticians and dermatologists. 

Both zinc oxide and titanium oxide are natural and safe, but zinc oxide is considered more effective and its UV absorption spectrum is better than titanium oxide. It is also the only sunscreen active ingredient that is FDA approved for babies under 6 months of age and children.

Because of the massive barrier minerals put on skin, some of these leave a white cast making it more difficult to fully blend onto skin. To fix this issue, many companies are developing lighter formulas which provide a smooth appearance and less of a white cast. 

Physical sunscreens last longer than their chemical counterparts because they tend to degrade slower when exposed to the UV rays.

If you’re ready to head out into the sun, physical sunscreen is your best bet. Once you apply, you’re protected and don’t have to wait before sun exposure.

They only have a few ingredients compared to chemical sunscreens which makes them a great choice for people with sensitive skin and avoids putting harmful chemicals on your body. 

One of our favorites is Supergoop! 100% Mineral Mist with Marigold Extract.

Chemical Sunscreen

Chemical sunscreens use active ingredients that absorb UV radiation, converting it to heat and preventing it from penetrating the skin. They usually contain one or more of these ingredients: Oxybenzone, Avobenzone, Octisalate, Otocrylene, Homosalate, Avobenzone, and Octinoxate.

The worst of these is Oxybenzone. It is a known reef-killer and causes an immune response when applied to skin and exposed to sun. The EWG does not recommend using sunscreens with Oxybenzone, also known as Benzophenone-3, because it is a known photoallergen. A photoallergen is when a chemical on skin comes into contact with the sun and creates an immune response causing inflammation. It has also been shown to increase absorption of a common pesticide called 2,4D.

The active ingredients in chemical sunscreens don’t need to be in high concentrations to work effectively. Because of this, they are usually lightweight and quickly absorbed into skin. They don’t leave a white cast like most mineral sunscreens so they’re good for wearing under makeup. 

Because of all the ingredients in chemical sunscreens, they increase the likelihood of irritation, inflammation, and allergic reactions. Plus, Oxybenzone is a known photoallergen. For people with rosacea, chemical sunscreens can be especially unhealthy because they increase inflammation and redness when it turns UV rays into heat and can exacerbate flushing.

Chemical sunscreens become effective 20 minutes after applying and tend to degrade quicker during sun exposure, however many brands add stabilizers to make them last longer.

A high quality chemical sunscreen we love is Supergoop! Everyday Sunscreen with Sunflower Extract.

To Sum it Up

Physical sunscreens overall are safer and healthier for your skin and as formulas improve and awareness about toxic chemicals grows, these mineral sunscreens are quickly growing in popularity. Many companies are working to create chemical sunscreens safer and less irritating to skin and have eliminated Oxybenzone completely. Finding the best sunscreen for your skin is sometimes a process of trial and error but a great place to start is by finding a quality-driven brand and going from there.